I'm pretty sure in every webhost terms of service I've ever read they leave language in to kick you out if you are degrading the service for others. Turns out a prolonged DDoS attack is degrading the service for others. The bigger cloud providers are drastically less likely to drop you but now you're paying a premium on hosting.
I'd love to see someone suing the host for damages. The contract binds them as much as it binds you.
Sounds like a good way to have your next gaming rig financed.